Wet or "uncured" spray polyurethane foam (SPF) materials containing unreacted methylene diphenyl diisocyanates (MDI) have been proposed as an Initial Priority Product. These products are used for home and building insulation, weatherizing and sealing, and roofing.

Exposure to MDI has been shown to cause occupational asthma. Asthma is common among workers in the polyurethane industry. Do-it-yourselfers are also at risk when using these products without appropriate personal protection. Users of SPF may become more sensitive to MDI after just one or two exposures to the unreacted materials.

Supporting Documents

The following downloadable documents summarize information compiled by DTSC as of March 13, 2014. As the department receives additional information through workshops and other communications, it may modify the description of the chemical(s) or product or both. Such changes, and DTSC's updated rationale for selecting this proposed Priority Product, will be reflected in the official rulemaking file. In using these materials, readers should consider the following:

These documents are not regulatory documents and have no force of law.

The department is not asserting that the product cannot be used safely, only that there is a potential for exposure of people or wildlife to the Chemical of Concern in the Priority Product and that such exposure has the potential to cause or contribute to significant or widespread adverse impacts.

DTSC requests that interested stakeholders provide data on the chemical and product described in this document to assist us in the discernment process that will lead to our regulatory proposal.